Transcatheter Aortic Valve Replacement in Bicuspid Aortic Valve Stenosis

Flavien Vincent, MD, PhD; Julien Ternacle, MD, PhD*; Tom Denimal, MD; Mylène Shen, MSc; Bjorn Redfors, MD, PhD; Cédric Delhaye, MD; Matheus Simonato, MD; Nicolas Debry, MD; Basile Verdier, MD; Bahira Shahim, MD, PhD; Thibault Pamart, MD; Hugues Spillemaeker, MD; Guillaume Schurtz, MD; François Pontana, MD, PhD; Vinod H. Thourani, MD; Philippe Pibarot, DVM, PhD; Eric Van Belle, MD, PhD

Disclosures

Circulation. 2021;143(10):1043-1061. 

In This Article

Outcomes of TAVR Versus SAVR: Do we Need a Randomized Trial?

To date, studies comparing TAVR and SAVR have been only observational. The propensity score matching study by Elbadawi et al is the largest study (n=975 patients in each arm) and compared periprocedural outcomes between TAVR versus SAVR in BAV patients.[25] In-hospital mortality (3.1%) and serious adverse events were similar between the 2 groups, while TAVR was associated with a higher rate of PPI (13.8% versus 4.6%; P<0.01) but a lower rate of bleeding and transfusion. Length of hospital stay was also shorter after TAVR versus SAVR (4 days versus 7 days; P<0.01). This result is promising for TAVR, but should be interpreted with caution because major information was lacking (eg, type of THV, rate of equal or greater than moderate PVR, and absence of long-term follow-up), data were retrospectively obtained from codes of large healthcare databases (National Inpatient Sample), and residual confounding factors could not be eliminated. While only a direct head-to-head comparison study of TAVR versus SAVR will confirm the efficacy and safety of TAVR in BAV patients (Figure 4), it is reasonable to question whether a randomized trial could be practically conducted. Given that TAVR is well-established in the high- and intermediate-risk population, we can anticipate that some physicians and the majority of patients may be reluctant to participate. Conversely, SAVR remains the first-line therapeutic option in lower risk and younger BAV patients. Thus, the targeted population for an RCT should be those who are at low risk for surgery (STS score <4%), or at intermediate risk but are <75 years of age, eligible for a bioprosthetic valve (≥55 years of age), and with aorta dilation <50 mm. AV and aortic root anatomy should be evaluated by a CT core laboratory to determine the BAV type and TAVR feasibility. A potential approach for such RCT could be a randomized noninferiority trial stratified on surgical risk and severity of aortopathy with a primary composite end point of all-cause death, stroke, equal or greater than moderate PVR and rehospitalization at a minimum of 2 year follow-up. The follow-up should be annual for 10 years to detect valve and aorta-related events such as leaflet thrombosis, structural valve degeneration and aortic dissection, aneurysm, or aorta intervention. Based on an expected event rate comparable to that previously observed in TAV patients, we can estimate that the sample size would be between 1000 and 1500 patients depending on the noninferiority margin. Patients excluded for AV anatomic considerations but who underwent SAVR or TAVR should also be included in a registry and followed up to assess clinical outcomes in this population with unfavorable anatomy.

Figure 4.

Established and missing evidence for TAVR for patients with BAV.
BAV indicates bicuspid aortic valve; BE, balloon expandable; CT, computed tomography; PVR, paravalvular regurgitation; TAV, tricuspid aortic valve; TAVR, transcatheter aortic valve replacement; and THV, transcatheter heart valve.

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